The present invention pertains generally to a video monitor connected to various computer systems and, more particularly, relates to an adjustment system for the video monitor which can perform image quality adjustment operation by using a microprocessor to ensure an optimum image quality when connected to a computer system.
A microprocessor-controlled video monitor which can automatically adjust image quality adjustment parameters in accordance with the operation of different computer systems is conventionally known in the art (Japanese Unexamined Patent Publication No. 3-35287).
To maintain an optimum image quality, the video monitor of this kind is so constructed that operating parameters of its individual circuits, such as a video amplifier circuit, a vertical deflection circuit and a horizontal deflection circuit, are set to match a computer system to which the video monitor is connected. A control processor performs image quality adjustments by setting specific parameters of the video monitor through a digital-to-analog (D/A) converter.
Specific parameter settings suitable for various computer systems are readily stored in a nonvolatile memory in the aforementioned conventional video monitor. The control processor reads parameter settings suited to the computer system connected to the video monitor from the nonvolatile memory and alters, or corrects, current parameter settings.
The aforementioned video monitor also allows manual adjustment of the individual parameters. To make this possible, the video monitor is provided with a plurality of icons representative of the adjustable parameters, associated with correspondingly arranged light-emitting diodes and input switches for user inputting.
The conventional video monitor thus constructed enables an operator to recognize a selected icon by lighting a corresponding light-emitting diode. One drawback of this arrangement is that the operator can not perform adjustment operation unless he, or she, is fully aware of the content of each icon and skilled in every adjustment procedure. Another drawback of the conventional arrangement is that the operator can not carry out adjustments while observing a displayed image. This is because the operator is allowed to set a parameter corresponding to each selected icon only in one direction, a positive-going direction only for contrast adjustment, for example, in a single adjusting action, and input switches for incrementing and decrementing the setting of each parameter are provided independently of each other, requiring successive operations. The image quality adjustment operation has therefore been complicated and taking a lot of time.
This invention has been made in the light of the aforementioned problems of prior art technology. Accordingly, it is a principal object of the invention to provide a video monitor adjustment system which significantly simplifies adjustment operation by allowing an operator to perform a fingertip operation in an integrated manner while observing an on-screen display.
A video monitor adjustment system which has achieved the aforementioned object of the invention is characterized in that it comprises an on-screen display controller circuit which displays a plurality of adjustment items in the form of icons on a display screen of a video monitor, an input device used for selecting one of the icons displayed on the screen and setting a parameter corresponding to the selected icon, the input device including an operating element into which four-way input switches for specifying upward, downward, leftward and rightward directions and an input confirmation switch are integrally incorporated, and a image quality controller which identifies a selected adjustment item based on an icon selection command entered through the input device and adjusts image quality adjustment parameters of the video monitor in accordance with parameter setting operation.
In this invention, the aforesaid input device may be constructed in such a way that the four-way input switches and the input confirmation switch are operated by using a common operating switch panel. Alternatively, the aforesaid input device may be constructed in such a way that the four-way input switches are operated by using a common operating switch panel and the input confirmation switch is operated by using another operating element.
The aforesaid on-screen display controller circuit may also display the content of each icon at the same time in the form of a visual message.
The aforesaid four-way input switches may be divided into two groups, one group including switches usable for incrementing or decrementing the setting of one of two parameters, and the other group including keys invalid.
The aforesaid image quality controller and on-screen display circuit may work together to display a plurality of icons used for parameter setting based on a time-division scheme. Furthermore, a plurality of icons used for parameter setting may be displayed all together for each adjustment item. It is preferable that the icons displayed together individually correspond to the four-way input switches, and an icon selected from the icons displayed together be emphasized in its appearance for ease of identification.
According to the invention, a microprocessor serving as the image quality controller transmits adjustment signals to such circuits as a video amplifier circuit, a vertical deflection circuit and a horizontal deflection circuit via a D/A converter of the video monitor upon receiving a command entered through the input device and adjusts parameters of the individual circuits.
The adjustment items include brightness, contrast, horizontal size, horizontal position, vertical size, vertical position, pincushion distortion, pincushion balance, trapezoidal distortion, parallelogram distortion, horizontal convergence, vertical convergence, horizontal moire correction, vertical moire correction, vertical linearity, vertical linearity balance, top and bottom corner distortions, top and bottom corner distortion balances, and tilt, for example.
The microprocessor can overlay a message explaining each adjustment item on the screen of the video monitor through the on-screen display circuit. The message appears on the screen for each individual adjustment item, providing an appropriate instruction to an operator. Since an input signal is externally entered through an input terminal of the video monitor at this time, an image used for adjustment operation, such as a crosshatch pattern, is also displayed on the screen. Therefore, the message is overlaid on the image used for adjustment.
On-screen messages may include in their contents any graphical symbols including icons in addition to an arbitrary character string. Each message may be presented with each character surrounded with a frame, or individual characters may be displayed without special circumscription.
A combination of the four-way input switches and the input confirmation switch enables convenient operation; the four-way input switches may be used for selecting adjustment items and for incrementing and decrementing parameter settings, while the input confirmation switch may be used for setting the selected adjustment item and the adjusted parameter. When the four-way input switches are used in this way, upward and rightward directions may be used for incrementing operation, and downward and leftward directions for decrementing operation. With this arrangement, a selected parameter can be varied on a real-time basis through the microprocessor in accordance with the duration of time each switch is held pressed.
If the input confirmation switch is pressed when an optimum image quality has been achieved, the microprocessor writes the value of the selected parameter at that moment into a nonvolatile memory to preserve it.
If the input device is an operating switch unit into which the four-way input switches and the input confirmation switch are integrally incorporated, the operator can selectively operate the four-way input switches and the input confirmation switch only by slightly changing his, or her, switch pressing position. This enables the operator to complete each adjustment sequence while observing the screen of the video monitor,-without having to look at the operating switch unit. It is preferable that the operating switch unit operated in this manner have a physical size that is suitable for a fingertip adjustment, and projecting markings corresponding to the four-way input switches and the input confirmation switch be formed on its surface.
If the input device is divided into two operating switch units, one combining the four-way input switches and the other incorporating the input confirmation switch, the operator can adjust the image quality with his, or her, both hands, using a fingertip of the left hand to manipulate one operating switch unit and a fingertip of the right hand to manipulate the other operating switch unit.
If the four-way input switches are divided into two groups, each for incrementing or decrementing the settings of two parameters, it would become possible to adjust two closely interrelated parameters at the same time, and adjustment operation can be performed more quickly. Specifically, the two closely interrelated parameters may be contrast and brightness, horizontal size and vertical size, horizontal position and vertical position, pincushion balance and pincushion distortion, parallelogram distortion and trapezoidal distortion, horizontal convergence and vertical convergence, horizontal moire correction and vertical moire correction, for example. It will be recognized from these examples that it is possible to combine parameters which are often adjusted interdependently in ordinary adjustment work as well as those parameters which can be combined with each other based on their conceptual similarity.
In this case, the microprocessor can make it even easier to select a desired adjustment item from those shown on a submenu window by presenting icons, which prompt the operator to increment or decrement the settings of the two parameters, at the same position within the submenu window based on a time-division scheme. Since the selected adjustment item, or icons corresponding to that adjustment item, are alternately displayed with the lapse of time, the operator can intuitively recognize the content of adjustment and carry out the operation.
Alternatively, the microprocessor may simultaneously display functions of the individual directional input switches by presenting all icons, corresponding to incrementing and decrementing operations of the two parameters, on an adjustment screen at the same time, rather than presenting them based on a time-division scheme. More particularly, icons corresponding to the incrementing and decrementing operations of the two parameters may be displayed at top, bottom, left and right positions on the screen so that they correspond to the incrementing and decrementing functions of the four-way input switches, and an icon corresponding to a directional input switch pressed by the operator may be emphasized in its appearance, for instance. This arrangement would enable the operator to distinctly recognize the content of each operation. Preferably, the icon should be emphasized by showing it in an inverted video, or temporarily surrounding it by a box or underscoring it. This is because a video emphasis technique of this kind is effective for saving the capacity of the nonvolatile memory, when compared to a method of displaying a completely different icon.
According to the invention, it is possible to present the individual adjustment items on the screen of the video monitor to allow the operator to select a desired adjustment item, as well as messages necessary for carrying out parameter setting and other adjustment operations on the same screen. This permits the operator to easily adjust the image quality within a short period of time. Moreover, the integrated four-way input switches make it possible to perform the adjustment operations without looking at the fingertips and to increment or decrement the settings of two parameters at the same time. This provides such advantageous effects that operator input efficiency is significantly improved, and this enables the operator to execute adjustment work in a reliable and efficient manner.